* [PATCH] ACPI / extlog: Check for RDMSR failure
@ 2020-09-27 21:50 Ben Hutchings
2020-10-02 17:02 ` Rafael J. Wysocki
0 siblings, 1 reply; 2+ messages in thread
From: Ben Hutchings @ 2020-09-27 21:50 UTC (permalink / raw)
To: linux-acpi; +Cc: 971058, jim
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extlog_init() uses rdmsrl() to read an MSR, which on older CPUs
provokes a error message at boot:
unchecked MSR access error: RDMSR from 0x179 at rIP: 0xcd047307 (native_read_msr+0x7/0x40)
Use rdmsrl_safe() instead, and return -ENODEV if it fails.
Reported-by: jim@photojim.ca
References: https://bugs.debian.org/971058
Cc: stable@vger.kernel.org
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
drivers/acpi/acpi_extlog.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
index f138e12b7b82..72f1fb77abcd 100644
--- a/drivers/acpi/acpi_extlog.c
+++ b/drivers/acpi/acpi_extlog.c
@@ -222,9 +222,9 @@ static int __init extlog_init(void)
u64 cap;
int rc;
- rdmsrl(MSR_IA32_MCG_CAP, cap);
-
- if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr())
+ if (rdmsrl_safe(MSR_IA32_MCG_CAP, &cap) ||
+ !(cap & MCG_ELOG_P) ||
+ !extlog_get_l1addr())
return -ENODEV;
rc = -EINVAL;
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^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] ACPI / extlog: Check for RDMSR failure
2020-09-27 21:50 [PATCH] ACPI / extlog: Check for RDMSR failure Ben Hutchings
@ 2020-10-02 17:02 ` Rafael J. Wysocki
0 siblings, 0 replies; 2+ messages in thread
From: Rafael J. Wysocki @ 2020-10-02 17:02 UTC (permalink / raw)
To: Ben Hutchings; +Cc: ACPI Devel Maling List, 971058, jim
On Mon, Sep 28, 2020 at 12:27 AM Ben Hutchings <ben@decadent.org.uk> wrote:
>
> extlog_init() uses rdmsrl() to read an MSR, which on older CPUs
> provokes a error message at boot:
>
> unchecked MSR access error: RDMSR from 0x179 at rIP: 0xcd047307 (native_read_msr+0x7/0x40)
>
> Use rdmsrl_safe() instead, and return -ENODEV if it fails.
>
> Reported-by: jim@photojim.ca
> References: https://bugs.debian.org/971058
> Cc: stable@vger.kernel.org
> Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
> ---
> drivers/acpi/acpi_extlog.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/acpi_extlog.c b/drivers/acpi/acpi_extlog.c
> index f138e12b7b82..72f1fb77abcd 100644
> --- a/drivers/acpi/acpi_extlog.c
> +++ b/drivers/acpi/acpi_extlog.c
> @@ -222,9 +222,9 @@ static int __init extlog_init(void)
> u64 cap;
> int rc;
>
> - rdmsrl(MSR_IA32_MCG_CAP, cap);
> -
> - if (!(cap & MCG_ELOG_P) || !extlog_get_l1addr())
> + if (rdmsrl_safe(MSR_IA32_MCG_CAP, &cap) ||
> + !(cap & MCG_ELOG_P) ||
> + !extlog_get_l1addr())
> return -ENODEV;
>
> rc = -EINVAL;
Applied as 5.10 material, thanks!
^ permalink raw reply [flat|nested] 2+ messages in thread
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2020-10-02 17:02 ` Rafael J. Wysocki
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